phy: phy-brcm-sata: Allow configuration SATA AFE TX amplitude

Read the 'brcm,tx-amplitude-millivolt' property from Device Tree and
propagate its value into the appropriate test transmit register to
change the TX amplitude.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20201022205056.233879-3-f.fainelli@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/broadcom/phy-brcm-sata.c b/drivers/phy/broadcom/phy-brcm-sata.c
index 53942973f508d8ab52e1e7060b368924aaaeaee5..3ecf41359591a81b46d55d412c37c20dd1895e88 100644 (file)
--- a/drivers/phy/broadcom/phy-brcm-sata.c
+++ b/drivers/phy/broadcom/phy-brcm-sata.c
@@ -65,6 +65,7 @@ struct brcm_sata_port {
        bool ssc_en;
        enum brcm_sata_phy_rxaeq_mode rxaeq_mode;
        u32 rxaeq_val;
+       u32 tx_amplitude_val;
 };
 
 struct brcm_sata_phy {
@@ -84,6 +85,10 @@ enum sata_phy_regs {
        BLOCK0_SPARE_OOB_CLK_SEL_MASK           = 0x3,
        BLOCK0_SPARE_OOB_CLK_SEL_REFBY2         = 0x1,
 
+       BLOCK1_REG_BANK                         = 0x10,
+       BLOCK1_TEST_TX                          = 0x83,
+       BLOCK1_TEST_TX_AMP_SHIFT                = 12,
+
        PLL_REG_BANK_0                          = 0x050,
        PLL_REG_BANK_0_PLLCONTROL_0             = 0x81,
        PLLCONTROL_0_FREQ_DET_RESTART           = BIT(13),
@@ -379,6 +384,29 @@ static int brcm_stb_sata_16nm_ssc_init(struct brcm_sata_port *port)
        brcm_sata_phy_wr(port, RXPMD_REG_BANK, RXPMD_RX_FREQ_MON_CONTROL1,
                         ~tmp, RXPMD_MON_CORRECT_EN | value);
 
+       tmp = GENMASK(15, 12);
+       switch (port->tx_amplitude_val) {
+       case 400:
+               value = BIT(12) | BIT(13);
+               break;
+       case 500:
+               value = BIT(13);
+               break;
+       case 600:
+               value = BIT(12);
+               break;
+       case 800:
+               value = 0;
+               break;
+       default:
+               value = tmp;
+               break;
+       }
+
+       if (value != tmp)
+               brcm_sata_phy_wr(port, BLOCK1_REG_BANK, BLOCK1_TEST_TX, ~tmp,
+                                value);
+
        /* Turn on/off SSC */
        brcm_sata_phy_wr(port, TX_REG_BANK, TX_ACTRL5, ~TX_ACTRL5_SSC_EN,
                         port->ssc_en ? TX_ACTRL5_SSC_EN : 0);
@@ -787,6 +815,10 @@ static int brcm_sata_phy_probe(struct platform_device *pdev)
                if (port->rxaeq_mode == RXAEQ_MODE_MANUAL)
                        of_property_read_u32(child, "brcm,rxaeq-value",
                                             &port->rxaeq_val);
+
+               of_property_read_u32(child, "brcm,tx-amplitude-millivolt",
+                                    &port->tx_amplitude_val);
+
                port->ssc_en = of_property_read_bool(child, "brcm,enable-ssc");
                if (IS_ERR(port->phy)) {
                        dev_err(dev, "failed to create PHY\n");